Gender differences in emphysema phenotype in smokers without airflow obstruction

¹ Dept of Clinical Sciences, Division of Radiology, University of Parma, Italy
² Division of Thoracic Surgery, Istituto Nazionale tumouri, Milano, Italy
³ Mario Negri Institute, Milano, Italy; and Institute of Medical Statistics and Biometry "G. A. Maccacaro", University of Milano, Italy
⁴ Division of Radiology, Istituto Nazionale tumouri, Milano, Italy
⁵ MeVis Research - Center for Medical Image Computing, Bremen, Germany
⁶ Dept of Respiratory Diseases, University of Modena and Reggio Emilia, Italy

^* To whom correspondence should be addressed. E-mail: nicolasve{at}tiscali.it.

	Abstract

Data on transgender differences in emphysema is limited to chronic obstructive pulmonary disease. We aimed to verify whether such differences exist also in smokers without airflow obstruction, weighting their influence on the relationship between emphysema and clinical features.

We evaluated both clinical and multidetector computed tomography (MDCT) data of 1011 heavy smokers recruited by a lung cancer screening project. MDCT scans were analyzed with a software allowing lobar quantification of emphysema features. For these measures, multiple regression models were applied to assess the gender effect, after allowance for age, body mass index (BMI), smoking history, FEV₁ and FVC.

The final study cohort consisted of 957 smokers without airflow obstruction. Women, compared with men, exhibited an emphysema phenotype less extensive in each pulmonary lobe and characterized by smaller emphysematous areas and less concentrated in the core of the lung. However, in females the increase of emphysema with age was more pronounced and displayed a more significant relationship with the FEV₁% decline; conversely, in men there was a stronger association with the decrease in BMI.

Men and women respond differently in type and location of lung damage due to tobacco exposure. In smokers, gender influences the relationship between emphysema and clinical features.